Electrochemical wound therapy device

ABSTRACT

A disposable wound-healing device is disclosed that incorporates a housing having a fluid-impermeable material having a cavity and a perimeter that can be sealed in an air-tight manner over a wound region of a patient. The device is capable of producing a negative pressure over the wound region by either removing oxygen from within the cavity, or absorbing fluid into the cavity and then removing the fluid from the cavity. The oxygen may be removed via chemical absorption, by an electrochemical cell or by a chemical reaction that cannibalizes oxygen from the cavity. The fluid may be removed through the use of osmotic or electro-osmotic cells, or through a one-way valve. The negative partial pressure over the wound region promotes healing.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.10/657,820 filed on Sep. 8, 2003 and entitled DEVICE AND METHOD FORWOUND THERAPY, which issued on Apr. 22, 2008 as U.S. Pat. No. 7,361,184,incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates in general to a device and method for woundtherapy that is capable of treating a variety of wound types, includinginfection wounds, burn wounds, diabetic ulcers, post amputation wounds,surgical wounds, and the like. Specifically, the present device isrelated to wound treatment devices and methods that utilize negativepressure therapy.

2. Background Art

The concept of using negative pressure in the treatment of wounds hasbeen around for decades. For example, some recent U.S. patents,including U.S. Pat. Nos. 5,636,643, 5,645,081 and U.S. Pat. No.6,142,982, describe a number of different types of negative pressurewound healing equipment. The equipment described and disclosed in theprior art, however, is bulky and requires complicated associatedequipment such as suction pumps, vacuum pumps and complex electroniccontrollers. Thus, the present devices that utilize negative pressuretherapy are bulky, power intensive, costly and non-disposable.

It is therefore an object of this invention to provide a negativepressure wound therapy device that is self-contained and entirelydisposable after use.

Additionally, it is also an object of this invention to provide a deviceand method for creating a negative partial pressure without the use ofelectrically/chemically powered suction and/or vacuum pumps.

It is also an object of this invention to provide a device and methodfor creating a suction environment around a wound, without the need forelectrically-produced suction or the use of a vacuum pump.

These and other objects will become apparent to one of ordinary skill inthe art in light of the specification, claims and drawings appendedhereto.

SUMMARY OF THE INVENTION

The present invention includes a disposable, self-integrated woundtherapy device that does not require an external power source. Thedevice includes a gas or fluid impermeable housing with a cavity havingat least one opening. The housing also includes at least one of anoxygen absorber/remover or a fluid absorber/remover. The housing mayfurther include an antimicrobial porous fluid absorbing material withinor adjacent the cavity. In one embodiment the device includes a sensorto detect the pressure or oxygen level over the wound and within thecavity. In another embodiment the device further comprises means forfilling the cavity of the housing with oxygen or fluid before the deviceis activated.

In a preferred embodiment, the device comprises a disposable devicehaving a cavity capable of encircling and sealing over an area of woundto be treated on the patient. In such embodiment, the cavity furthercomprises a fluid absorbing antimicrobial porous pad, oxygen absorber oroxygen remover, each of which is capable of creating negative pressureover or within the wound region. The oxygen absorber or remover can beeither a chemical absorber or an electrochemical cell. In case ofelectrochemical cell, an associated electronic circuit may beincorporated to actuate the cell.

The chemical absorbers could include any number of materials that absorbor adsorb oxygen upon contact, but specifically may include metalpowders, activated carbon, catalyst materials, zeolites and mixtures andcombinations thereof. Similarly, any number of electrochemical celltypes may additionally be used, as long as they consume oxygen as a partof their operation. For example, metal/air cells such as zinc/air,magnesium/air, aluminum/air, and iron/air cells may preferably be usedwith this invention. Additionally, a Nafion-based cell may also be used.

In another preferred embodiment the device comprises a disposable devicecomprising a cavity capable of encircling and sealing over an area ofthe wound to be treated on the patient. In such embodiment the cavityfurther comprises either a chemical or electrochemical based fluidremoval system or fluid absorbing system. The disposable device furthercomprises means for filling the cavity with fluid before activation ofthe device, such as an antimicrobial fluid hydrogen peroxide, water andthe like.

In another preferred embodiment, the wound therapy device may includematerials for absorbing a fluid within the cell, such as anantimicrobial fluid absorbing porous pad placed in communication withthe wound and at least partially enclosed within the cavity of thehousing. The porous material can include, for example, an adhesive mesh,or a super-absorbent polymer material. Alternatively, in anotherembodiment, the porous pad may be external to the device itself; and acapillary or other similar fluid conduit can be placed into contact withwound fluids on one end and the absorbing materials on the other.

The housing may be constructed from a number of materials, as long asthey are fluid-impermeable, including steel, aluminum, copper alloys,and dense plastics such as polypropylene, polyvinyl chlorides,polyethylene, berex, nylon and Teflon.

In another preferred embodiment the device further comprises means forheat generation during oxygen removal or absorption/adsorption.

As an alternative to the above devices, pressure bands could be utilizedto help close open wound regions instead of, or in conjunction with thenegative pressure treatment devices. These bands would be placed oneither side of a wound region, and create a downward pressure into thepatient's skin. Alternatively, the pressure bands could provide apressure that, either directly or indirectly, forces the edges of theopen wound region towards one another. The amount of pressure to operatesuch bands would depend upon the particular application, but could be,for example, around 350 mmHg.

Preferably, a fluid-absorbing means is placed above the wound region,and used in conjunction with the pressure bands.

The invention further comprises a method for treating a wound comprisingthe steps of providing a gas impermeable housing having a cavity,positioning at least a portion of the wound within a cavity of thehousing and one or both of the steps of absorbing the oxygen withincavity of the housing and generating a partial vacuum within the cavity.

In an embodiment wherein the method of treating the wound comprises thesteps of providing a non-permeable housing having a cavity, positioningat least a portion of the wound within a cavity of the housing and bothof the steps of removing the oxygen from the cavity electrochemically,manually or chemically and generating partial vacuum within the cavity.

In another embodiment wherein the method of treating the wound comprisesfurther the steps of providing a housing having a cavity, positioning atleast a portion of wound within a cavity of the housing one or bothsteps of first filling the cavity with oxygen before activating themanual, chemical or electrochemical cell to remove or absorb the oxygenfrom the cavity and secondly, generating controlled vacuum within thecavity.

In another alternative embodiment wherein the method of treating thewound includes the steps of providing housing having a cavity,positioning at least a portion of the wound within a cavity of thehousing, and the steps of first filling the cavity with fluid such aswater removing the fluid (water) from the cavity and then using osmoticor electrochemical or electro-osmotic cell and thereby generating acontrolled vacuum within the cavity.

In another preferred embodiment, the method further comprises the stepsof providing oxygen to the wound cyclically by providing an impermeablehousing having a cavity, positioning at least portion of the woundwithin a cavity of the housing and the steps of first removing the airor oxygen and then filling back with air or oxygen in the cavity in aperiodic way and generating cyclic pressure of oxygen over the wound.

In an alternative embodiment of the present invention, negative pressuretherapy can be undertaken by reducing pressure within the wound itself.To that end, one embodiment of the present invention may include adisposable wound therapy device that has a housing with a cavitytherein, along with a perimeter surrounding the cavity, and means forremoving wound fluid out of a wound region, which removing means isintegrated into the housing. Such a removing means could include asuper-absorber polymer object, capable of drawing fluid out and awayfrom the wound region, such as to an external reservoir region, thuscausing a suction environment surrounding the wound. This embodimentcould operate with or without oxygen removing means.

If the pressure-band embodiment of the present invention is used, thewound region is treated by the method including the steps of placing atleast two pressure bands on opposite sides of a wound region of apatient, and applying pressure to the tissues surrounding the woundregion using the pressure band, thereby forcing the one side of thewound region towards the other, to, in turn, close the wound region.Additionally, it may be beneficial to include the step of removingexcess wound fluid from the wound region using a fluid absorbing orfluid removing means, such as a capillary conduit or an absorbentpolymer. Furthermore, utilizing the pressure bands with the sealingpatch, to cause a sub-atmospheric vacuum around the wound region, canprovide additional benefits.

It may likewise be beneficial to attach the pressure bands together, orto use an adhesive strip across the wound region, so as to force thewalls of the open wound region towards one another.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 comprises a cut-out view of one embodiment of the wound-healingdevice;

FIG. 1A comprises cut-out view of the wound-healing device,incorporating an oxygen injection device;

FIG. 1B comprises still another cut-out view of the wound-healingdevice, having a sponge;

FIG. 1C comprises a cut-out view of the wound-healing deviceincorporating capillary tubes;

FIG. 2A comprises a cut-out view of the wound-healing device,incorporating an electrochemical cell;

FIG. 2B comprises another cut-out view of the wound healing device withan electrochemical cell, additionally incorporating an oxygen sensingdevice;

FIG. 3A comprises a cut-out view of the wound-healing device,incorporating an osmotic cell;

FIG. 3B comprises a cut-out view of the wound-healing device,incorporating an electro-osmotic cell;

FIG. 4 comprises a cut-out view of the wound-healing device, which isresiliently deformable, incorporating a second adjacent fluid retentionchamber;

FIG. 5 comprises a cut-out view of one embodiment of the wound-healingdevice;

FIG. 5A comprises a cut-out view of the wound-healing device,incorporating a fluid-removal device;

FIG. 5B comprises a cut out view of another preferred embodiment of thewound-healing device, comprising a single fluid-absorption device; and

FIG. 6 comprises a perspective view of a pressure-band embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and described herein in detailspecific embodiments with the understanding that the present disclosureis to be considered as an exemplification of the principles of theinvention and is not intended to limit the invention to the embodimentsillustrated.

Referring now to the enclosed figures and in particular to FIG. 1, woundtherapy device (herein after “device”) is shown generally as 10. Such adevice is particularly useful in association with the therapy of surfacewounds on a patient. These wounds may include, but are not limited to,infectious wounds, burn wounds, diabetic ulcers and wounds, postsurgical wounds, bed source wounds, and the like. Additionally, suchdevices are contemplated for use in a variety of the fields, as would becontemplated by one or ordinary skill in the art.

Disposable device 10, as shown in FIG. 1 comprises gas-impermeable rigidhousing 102, means 104 for absorption of oxygen from cavity 130, means106 for absorption of wound fluids, and means 108 for sealing the devicealong a perimeter 116 of device 10. It is contemplated that the device10 is not only disposable in its entirety but also very light andinexpensive. It is also contemplated that the device is shaped like abandage, which can then be changed by the user multiple times.

Sealing means 108 can comprise a number of different structures.Preferably, sealing means 108 comprises sealing disc 132 with pull tab133. Alternatively, sealing means 108 could also include adhesive, oranother element that will create a substantially air-tight seal aroundperimeter 116 of device 10 upon operative positioning of same. Theair-tight seal protects the contents of cavity 130 during storage and/ortransportation of device 10.

In the embodiment incorporating sealing disc 132 for sealing means 108,pull tab 133 operates to break the seal around perimeter prior to use ofdevice 10. Once sealing disc 132 is removed by using pull tab 133 thedevice may be placed on a patient's wound in such a fashion that cavity130 incorporates the wound therein, and device 10 seals around perimeterof the wound. Housing 102 is preferably constructed from a rigid orsemi-rigid type material so that it is capable of retaining a vacuumspace surrounding the wound. As soon as the device is placed on thepatient's wound, oxygen absorbing means 104 starts absorbing oxygen inthe air around the wound, generating a vacuum within cavity 130. At thesame time, wound-fluid absorbing means 106 starts absorbing the fluidsin the wound. Continued absorption of both the oxygen and wound fluidwithin cavity 130 creates a vacuum within cavity 130, and surroundingthe wound region.

Sustained negative pressure over a wound region promotes tissuemigration and wound closure. Device 10 is preferably shaped like a patchor bandage that may be changed more than once a day. During the time thedevice is on patient's wound, a negative pressure is generated due tothe absorption of oxygen, thus the oxygen level around the wound is low(1-5%). When the device is removed after use the wound get exposed to21% oxygen in air. Thereafter, another patch may be applied, reducingthe oxygen partial pressure over the wound region. This alternateexposure of wound to oxygen level swings is also helpful in woundhealing.

Housing 102 may comprise any shape and is not limited to particularshape. Solely by way of example, and not to be limited thereto, housing102 may be sized and shaped so that cavity 130 of device 10 andperimeter 116 of device 10 are capable of sealing over the patient'swound. Housing 102 is also designed such that it is capable of holdingthe vacuum when the device is plated and sealed over a patient's skinaround the wound.

FIG. 1A shows the similar device as shown in FIG. 1, except that FIG. 1Adevice compromises one additional structure, namely means 110 forintroducing oxygen into cavity 130. Introducing means 110 allows apatient to introduce preferably pure or concentrated oxygen into thecavity, which is then absorbed by oxygen absorbing means 104. Thisabsorption, in turn, generates a stronger negative pressure over thewound of the patient. FIG. 1A additionally depicts device 10 asincluding antimicrobial fluid absorber 106 and capillary tubes 118.Oxygen absorbers 104 are placed in the cavity 130 at two places as shownin FIG. 1C. Device 10 shown in FIG. 1C allows the wound fluids to bepulled away from wound while simultaneously maintaining a negativepressure over the wound.

The device shown in FIG. 1D is similar to the device shown in FIG. 1Cexcept that, in FIG. 1D, device 10 additionally includes oxygenintroducing means 110 to, in turn, generate a stronger vacuum withincavity 130. In FIG. 1D, device 10 additionally comprises porous plasticantimicrobial sponge 106, compared to the device shown in FIG. 1C, whichhas a combination of capillary tubes 118 and antimicrobial sponge 106.

In all the above devices the vacuum is generated by using oxygenabsorption means 104. There are many chemical as well as electrochemicaloxygen absorbers. For example, Mitsubishi Gas Chemicals manufacturesAgeless® Z oxygen absorbers, which absorb oxygen through the oxidationof iron metal. Alternatively, small packets of oxygen absorbers andscavengers are available from Mitsubishi Chemical Corporation.Similarly, porous antimicrobial plastic for fluid absorption can beused, and are formed from composite materials made from absorbentplastics such as Polypropylene, polyethylene, and the like, as well asother materials such as silver oxide, metal peroxides, silver metal, andantimicrobial organic compounds.

FIGS. 2A and 2B depict similar devices to those shown in FIGS. 1, 1A, 1Band 1C in that they all are based on absorbing or removing oxygen fromcavity 130 of housing 102. FIGS. 2A and 2B, however, includeelectrochemical cells 140 for absorbing or removing oxygen from withincavity 130. In FIG. 2A, disposable device 10 is shown as having housing102, fluid absorbing antimicrobial porous pad 106, which is placed incavity 130 of housing 102, and oxygen sensor 112 to help gauge thenegative pressure within cavity 130. Preferably, electrochemical cell140 is sealed onto housing 102 such that cell 140 is capable of eitherremoving or absorbing the oxygen from within cavity 130, generating anegative pressure therein. Cell 140 may be activated by electroniccontrol circuit 142. Control circuit 142 allows user to set apredetermined and desired negative pressure setting within cavity 130for providing optimal wound treatment and therapy conditions for thewound.

The device shown in FIG. 2B is similar to device shown in FIG. 2A exceptthat in FIG. 2B device 10 additionally includes oxygen introducing means110, which is added to allow user to introduce oxygen into the cavity130, in turn enabling a strong negative pressure within cavity 130. Inthe embodiment shown in FIG. 2B, oxygen sensor 112 and electrochemicalcell 110 are combined through control circuit 142 so that, once thedesired level of negative pressure is reached within cavity 130 ofhousing 102, electrochemical cell 140 stops operating, and thusconsuming additional oxygen. By evaluating the oxygen level duringoperation, and controlling the operation of electrochemical cell 140accordingly, the negative pressure within cavity 130 can be regulated toa desired level. There are many ways in which the elements of device 10can be associated with, or placed within cavity 130, with only exemplaryembodiments and associations shown in FIGS. 2A and 2B.

U.S. Pat. Nos. 5,454,922, 5,607,572, 5,681,435, 5,707,499, 6,042,704,and 6,060,197 describe possible types of electrochemical cells that maybe used for removing oxygen from within cavity 130. For example,commercially available zinc-air cells can be used to remove oxygen. Inone preferred embodiment, electrochemical cells 140 within device 10could include either commercially available zinc-air cells, or any othermetal/air electrochemical cells to remove oxygen from cavity 130 ofhousing 102.

The devices shown in FIGS. 3A and 3B are osmotic and electro-osmoticcell-based devices, respectively.

As shown in FIG. 3A, housing 102 in this embodiment incorporates anosmotic cell 120 that includes an osmotic membrane (such as Nafion® orany cation or anion membrane) in communication with antimicrobial sponge106 placed within cavity 130 of housing 102 of device 10. Osmotic cell120 also includes saturated salt solution/or salt pellet 122 in chamber124 so that fluids from sponge are pulled into osmotic cell 120 andstored in chamber 122, thereby generating a vacuum within cavity 130 andover the wound. In this embodiment, and similar to oxygen introducingmeans 110, device 10 includes water injection means 125 to introducewater into cavity 130 so that sponge 106 is saturated with water. Againas in other devices such as shown in FIGS. 1, 1A, 1B, 1C, 1D, 2A and 2B,sealing means 108 is a sealing disc 132 which is pulled away by seal tab133 before the device is placed on the wound of the patient. Manyosmotic membranes are available commercially, any of which could beincluded in the present invention.

The operation of the devices shown in FIG. 3A is simple. First, sealingdisc 132 is removed by using pull tab 133, and sponge 106 is saturatedwith pure water. The device is then placed on the patient's wound. Oncein place, device 10 is activated. Within some minutes, the device beginsto generate negative pressure within cavity 130 and over the wound. Thedevice shown in FIG. 3B operates similarly, but requires the additionalsteps of activating electrochemical cell 140 so that cell 140 startstransporting the water from cavity 130 to chamber 124.

In FIG. 3B, electrochemical cell 140 is a water removing cell, such asthe cell shown and described in U.S. Pat. No. 6,491,684.

The device shown in FIG. 4 is manually operated. The device compriseshousing 102 housing wall 103 that is elasticized, or “springy,” suchthat, when it is depressed by a user, it will squeeze and deform butreturn to its original shape, Many polymeric materials show thesecharacteristics, if manufactured with the right dimensions and designcharacteristics. Housing 102 of device 10 shown in FIG. 4 furthercomprises cavity 130 filled with antimicrobial porous fluid absorbingpad 106. Housing 102 further comprises one way valve 150 sealed intohousing 102 such that the fluid from cavity 130 can be squeezed out ofcavity into a chamber 152 filled with antimicrobial fluid absorbingmaterial 154. Chamber 152 is attached to housing 102 as shown in FIG. 4.

The operation of the device shown in FIG. 4 is simple. First seal disc132 is removed using seal tab 133. Device 10 is then filled with waterso that antimicrobial sponge 106 is completely saturated with water. Nowthe device is placed on patients wound and sealed along perimeter 116 ofthe device with adhesive, adhering perimeter 116 to the skin surroundingthe wound to be treated. Once the device is firmly placed on thepatient, the device is squeezed from its top by the application ofpressure so that the water in sponge 106 is squeezed out through one wayvalve 150 into chamber 152, which is filled with water-absorbingantimicrobial sponge 154. Housing 102 then returns to original shapeafter squeeze. The removal of the fluid from within housing 102 createsa negative pressure over the wound. This negative pressure is controlledby number of squeezing cycles. It is also contemplated that if the woundgenerates additional fluids during the treatment the squeezing can bedone several times during the course of the treatment.

One additional and related embodiment can be seen in FIG. 5. In priorembodiments, such as those shown in FIGS. 1B, 1C, for example, fluidremoving means 106 provides an additional aid in the use of negativepressure therapy that utilizes sub-atmospheric pressure, or a vacuum.Fluid-removing means 106, however, can operate effectively withoutvacuum, as is shown in FIG. 5. In FIG. 5, device 10 is shown over woundregion 160, with capillary tubes 118 extending into wound region 160itself. Capillary tubes 118 are connected with external reservoir 152,and provide a conduit for the flow of fluid from out of wound region160, and into external reservoir 152. By removing wound fluid fromwithin wound region 160, the internal pressure of the wound isdecreased, and the wound region 160 is forced closed on itself, aidinghealing.

Device 10 is shown with capillary tubes 118 as a fluid deliverymechanism out of wound region 160 and into external reservoir 152. Otherembodiments and structures could similarly work as effectively,including using an alternative fluid delivery or removal means (such asan absorbent polymer strip overlying the wound region, for example,which simply absorbs the wound fluid, drying the wound and promotinghealing (see FIG. 5A)), or eliminating the fluid reservoir 152altogether, such as through a one-way valve, The essential elementsinclude removing the fluid from within the wound region so as to promotehealing of that area.

One especially preferred embodiment is shown in FIG. 5B, in which therubberized housing embodiment shown in FIG. 1B is combined with thefluid-absorbing structures of FIGS. 5 and 5A. It is preferred that thefluid-removing means in FIG. 5B comprises a super-absorbent polymermaterial 106 that is flexible in design, and which is connected to anexternal reservoir 152. Housing 102 includes a one-way valve 150, and isflexible and elastic such that a user may depress housing 102, releasingair from within housing 102, and reducing the pressure within the cavityof the device. At the same time, the polymer 106 (or otherfluid-removing means) is pulling fluid out of the wound region, andremoving that fluid from within cavity. This embodiment combinesexternal and internal negative pressure techniques.

It should be noted that any of the above techniques for reducing thepressure within the cavity of the devices (i.e. through air/oxygenremoval, or fluid removal), and within the wound itself (through woundfluid removal) can be beneficially combined for negative pressure woundtherapy.

In all of the above embodiments, where in the devices are disposable,these devices are capable of being discarded after use. The aboveteachings can be utilized with a wide variety of devices, and in anynumber of forms. For example, some contemplated devices into which theabove teachings can be incorporated include a glove, a shoe insole, or aspecialized sock. With these types of devices the patient can operatethe device and receive proper treatment while undertaking otheractivities. In addition, after the treatment is completed, the user canmerely dispose of the device. Indeed multiple disposable devices can beprovided to patient to, in turn, provide a full treatment plan whichconsists of a plurality of individual treatments with disposable devicesover predetermined period.

One additional alternative embodiment is shown in FIG. 6. In FIG. 6,pressure bands 200, 200′ are placed on either side of a wound region160, and exert a pressure on the tissue surrounding the wound region160, pushing the perimeter 210 of the wound region closed, to in turnclose the wound region. Such an embodiment may be combined with theoxygen-removing, fluid-removing, or wound-fluid removing embodimentsdiscussed above. In any case, by pressing the wound region together, thehealing of the wound region can be promoted.

Pressure bands 200 can comprise any number of materials, includingmedical-grade elastic bands and the like, which are capable of beingplaced proximate the wound region of a patient, and of creating anapproximately downward pressure on the skin of the patient. As shown inFIG. 6, pressure bands 200, 200′ basically comprise arm bands,surrounding the arm of a patient and pressing down on that arm.Alternative structures could function similarly, however, as long as thebands 200, 200′, through pressure on the surrounding tissues, promotehealing by helping to close the wound region.

One preferred way of aiding the closure of the wound region may be toinclude a connecting band or connecting means (not shown) between thepressure bands 200, 200′. Connecting means may be constructed from anyrigid or elastic material that would exert a force between pressurebands 200, 200′, to pull those bands towards each other. The lateralmovement of pressure bands 200, 200′, in combination with theapproximately downward pressure of those bands, will provide anadditional means to press the edges of the wound region together, inturn aiding the healing of the wound region.

Alternatively, it may be desirous to include adhesive strip 220 overwound region. Adhesive strip 220 comprises a strip of material, such asa medical bandage, that is capable of being adhered to two sides of thewound region, and to pull those sides together. Similar to theconnecting band or connecting means discussed above, adhesive strip 220is preferably used in conjunction with pressure bands 200, 200′ topromote wound healing.

Additionally, pressure bands 200, 200′ could be utilized with a numberof the other structures discussed above, including but not limited tothe fluid removing means or any other means for creating negativepressure inside or outside of the wound region.

In operation, the pressure bands are provided 200, 200′ to a patient,and applied in opposing but surrounding positions to the wound region ofthe patient. The patient places the pressure bands around the wound,which bands then exert a pressure on the surrounding tissues for aperiod of time, preferably an hour or more, but most preferably foraround 24 hours. The pressure that is exerted need not be significant,and preferably is around 350 mmHg of pressure. Once pressure is appliedthe wound region is at least partially closed, promoting healing.Preferably the pressure bands are combined with negative pressuretherapy for maximum benefit.

Preferably, in combination with the pressure bands, the wound region isat least partially closed by either connecting pressure bands 200, 200′together to exert a lateral pressure (not downward) on the wound region,or adhesive strip 220 may be used to do the same. In either case, thehealing of the wound region may be enhanced by physically closing theopen wound area of the wound region.

The foregoing description merely explains and illustrates the inventionis not limited thereto except in so far as the appended claims are solimited, as those skilled in the art who have the disclosure before themwill be able to make modifications without departing the scope ofinvention.

1. A disposable wound-therapy device comprising: a housing forming acavity therein, wherein the cavity communicates with at least oneopening adapted to encompass at least a portion of a wound region of apatient; a perimeter surrounding the at least one opening; means forsealing the perimeter to a surface of the patient proximate the woundregion; a porous sponge at least partially inside the cavity and capableof retaining a fluid therein; a chamber in communication with thecavity; and an electrochemical cell for removing the fluid from thesponge and transporting the fluid into the chamber.
 2. The wound-therapydevice of claim 1, wherein the electrochemical cell is integrated intothe housing.
 3. The wound-therapy device of claim 1, wherein theelectrochemical cell is an electro-osmotic cell.
 4. The wound-therapydevice of claim 3, wherein the electro-osmotic cell comprises an anodeand a cathode.
 5. The wound-therapy device of claim 3, wherein theelectro-osmotic cell comprises an osmotic membrane positioned betweenthe cavity and the chamber.
 6. The wound-therapy device of claim 5,wherein the osmotic membrane is a cationic membrane.
 7. Thewound-therapy device of claim 5, wherein the osmotic membrane is ananionic membrane.
 8. The wound-therapy device of claim 5, wherein theosmotic membrane is in fluidic communication with the porous sponge. 9.The wound-therapy device of claim 1, wherein the porous sponge comprisesan antimicrobial material.
 10. The wound-therapy device of claim 1,wherein the porous sponge is configured to be at least partiallyimpregnated with a fluid.
 11. A disposable wound-therapy devicecomprising: a housing forming a cavity, wherein the cavity communicateswith at least one opening adapted to encompass at least a portion of awound region of a patient; a perimeter substantially surrounding the atleast one opening to provide a seal between the cavity and a surface ofthe patient proximate the wound region; a retention chamber incommunication with the cavity; and an electro-osmotic cell having anosmotic membrane positioned between the retention chamber and the cavityto remove fluid from within the cavity and transport the fluid into theretention chamber.
 12. The wound-therapy device of claim 11, wherein theelectro-osmotic cell comprises an anode and a cathode.
 13. Thewound-therapy device of claim 11, wherein the osmotic membrane is acationic membrane.
 14. The wound-therapy device of claim 11, wherein theosmotic membrane is an anionic membrane.
 15. The wound-therapy device ofclaim 11, further comprising a porous sponge at least partially insidethe cavity to retain the fluid prior to removal.
 16. The wound-therapydevice of claim 15, wherein the porous sponge comprises an antimicrobialmaterial.
 17. The wound-therapy device of claim 15, wherein the poroussponge is configured to be at least partially impregnated with a fluidprior to use.
 18. The wound-therapy device of claim 15, wherein theosmotic membrane is in fluidic communication with the porous sponge.